Glomerulonephritis

Summary

Glomerulonephritis is a family of kidney diseases that can cause of renal failure at any age. The glomerulus and how it works is explained and there are links to further information on the different conditions.

Anatomy and functions of the glomerulus

The glomerulus is a tiny ball of capillaries (very small blood vessels inside bowman’s capsule) through which the urine is filtered.

The glomerular filtration rate (GFR) is the amount that is filtered. Usually, this is about 100ml per minute – only an espresso cupful, but this adds up to 150 litres per day! This is produced by the 2 million nephrons in the average healthy pair of kidneys in a young adult. 99% of this filtrate is re-absorbed, leaving one to two litres of urine to be passed each day.

The filter keeps blood cells and all large proteins (albumin, for example) in the blood and out of the urine.

With the natural aging process the GFR decreases very slowly. Usually this is not noticed and is not a problem. If the rate slows down markedly, as in a diseased kidney, symptoms and signs of kidney disease result.

What goes wrong in glomerulonephritis?

Some typical signs and symptoms can be:

High blood pressure

A urine test may reveal blood in the urine (haematuria)

A urine test may reveal protein in the urine (proteinurea)

Swelling (oedema).

Nephrotic syndrome

This can occur where there is a severe protein leak from the kidneys caused by glomerulonephritis. Severe oedema, usually occurring in the ankles, can have a number of possible causes.